This invention relates to a parturition warning device for animals and has particular application to such a device for farm animals such as mares and cows.
It is always desirable, and often essential, to supervise large farm animals giving birth so that the supervising personnel can take such hygiene measures as may be desirable during and after the birth and can intervene when necessary to assist the delivery. A difficulty is that the exact time when delivery will start is difficult to determine in advance and, without a parturition warning device, the supervising staff must be on duty well in advance of the birth and may spend many long and tedious hours of waiting before the animal requires assistance.
Parturition devices are known and in, for example, British patent specification No. 632827 there is disclosed an electric alarm device comprising a contact device adapted to be attached to the mother animal and to be connected to an electric circuit including signal means, the contact device being provided with an operating member extending before the vagina of the mother animal, so as to establish a contact and close the electric circuit at the beginning of the litter, characterized in that the operating member of the contact device comprises a brace pivotably mounted on a contact casing adapted to be attached to the mother animal, such brace being resiliently held against the vagina of the mother animal and the arms of the brace being spaced apart, so as to permit urine and faeces of the mother animal to escape freely therebetween, the contacts in the contact casing being closed when the brace is turned upwards by the matter extruded from the vagina at the beginning of the litter.
A serious disadvantage of this prior art construction is that the arms of the brace are spaced apart at the level of the vagina and the amniotic sac can become wedged between the arms or, if the sac is pierced, the paws or feet of the animal being born can become wedged between the arms or pass one on either side of one or both arms. In such a case damage to the sac or the young animal may take place before the warning device is actuated.
In a more recently proposed parturition warning device a body is introduced into the vagina of the animal and, when the animal is erect and the body is expelled by the amnoiotic sac, the body falls downwardly to actuate the warning device. A disadvantage with this device is that, when the pregnant animal is lying, the body is expelled substantially at right angles to the intended path and the warning device is not actuated thereby.